Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease of unknown etiology and is characterized by a relentless progression to death - only 20 to 30% of IPF patients survive 5 years or longer after their diagnosis. Conventional management of IPF has been primarily based on the concept that suppressing inflammation would prevent progression to fibrosis. Clearly, this approach has failed;there is no effective treatment currently in use. The purpose of this application is to participate in the IPF Clinical Research Network (IPF-CRN) whose goal is to evaluate new and existing approaches for the management of IPF and to disseminate the findings generated from these studies to the medical community. In support of this application, we present two protocols that address important clinical questions, test novel therapeutic approaches for IPF, and require a multicenter, academic research network for completion. Specific Aims: 1) to assemble a multidisciplinary group of clinical and basic scientists to collaborate in the design and implementation of therapeutic trials for the treatment of patients with newly diagnosed IPF, as part of the multicenter IPF Clinical Research Network;and 2) to use the clinical research infrastructure established by the UCSF Interstitial Lung Disease Center of Excellence (ILD-COE) to implement multicenter clinical trials conducted under the auspices of IPF-CRN. Protocol 1: A randomized, double-blind, placebo-controlled, multicenter trial of prednisone plus azathioprine in the treatment of IPF. Protocol 2: A randomized, double blind, placebo controlled, multicenter trial of interferon gamma-1b plus pirfenidone in the treatment of IPF. (End of Abstract)